The present invention relates to a disk reproducing apparatus, and particularly to a disk reproducing technique suitable for use in reproducing data at an N time normal speed from a disk on which main information has been recorded together with a subcode of time information or the like, such as a digital audio disk.
There is a known an example of data reproduction in which an intermittent access results when the information reading means is inadvertently moved by an external force or the like during N-time normal speed reproduction of a disk where N is a positive integer. That is, as described in JP-A-62-150560, (Shibuya) digital audio data reproduced from a compact disk (CD) is written in a memory, but when the information reading means inadvertently skips over tracks, it is moved back to its previous position from which the skipping occured. At this time, the writing of the data reproduced from the disk into the memory is stopped and the memory is read at a constant period of the sampling frequency. Thus, the digital-to-analog converted data can be continuously reproduced.
In this known method, during the period in which the information reading means is inadvertently moved, or skips over tracks and is then moved back to the original correct position, no noise occurs, and the reproduction is not interrupted, or abnormally carried out. However, data control is not performed for making data precisely continuous. This is because although the subcode of time information is produced in time with the disk reading operation, the audio data is first written in a memory in order that the rotation irregularity of the disk can be absorbed, and is read thereafter under the control of a crystal oscillation frequency. Thus, the subcode and the audio data cannot be made precisely coincident in one-to-one correspondence.